Entry Delay not working on contact sensor

Hi, Seeking help on Entry Delay not working properly on our contact sensor.We have contact sensors installed on our front door and back door, and under the Home Mode, I have set up an Entry Delay of 60s so that I can disarm before the alarm gets triggered.While the front door sensor works just fine, the back door contact sensor does not. As soon as I open the door, the alarm goes off. Is this a set-up issue or something? I already checked and made sure the set-ups are identical for both the front and the back door. Any insights will be appreciated.